package servlet.image;

import servlet.image.UploadImageServlet;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;

@WebServlet(name = "GetUploadServlet", value = "/GetUpload/*")
public class GetUploadServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 获取资源地址
        final String uri = request.getRequestURI();
        // 提取文件名
        final String filename = uri.replaceAll(".+/GetUpload/(.+)", "$1");
        // 设置返回的内容类型
        // html ==> text/html, jpg ==> image/jpeg
        final String mimeType = request.getServletContext().getMimeType(filename);
        response.setContentType(mimeType);

        // 将文件返回给浏览器
        // java.io流
        String path = UploadImageServlet.IMAGE_PATH + filename;

        try (FileInputStream fis = new FileInputStream(path)){
            byte[] buffer = new byte[1024];
            int count;
            final ServletOutputStream out = response.getOutputStream();
            while ((count = fis.read(buffer)) > -1){
                out.write(buffer, 0, count);
            }
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }
}
